Villefranche-sur-Mer in stormy weather, winter 2011 - Photo : J.-M. Grisoni
Villefranche-sur-Mer in stormy weather, winter 2011 - Photo : J.-M. Grisoni
Villefranche-sur-Mer in stormy weather, winter 2011 - Photo : J.-M. Grisoni
Phytoplankton bloom observed by the ocean color sensor MODIS onboard NASA satellite Terra in May 2010. The bloom spreads broadly in the North Atlantic from Iceland to the Bay of Biscay - Source : NASA's Earth Observatory (http:/earthobservatory.nasa.gov)
Phytoplankton bloom observed in the Barents Sea (North of Norway) in August 2010 by the ocean color sensor MODIS onboard NASA satellite Aqua. Changes in ocean color result from modifications in the phytoplankton composition and concentration. The green colors are likely associated with the presence of diatoms. The shades of light blue result from the occurrence of coccolithophores, phytoplankton organisms that strongly reflect light due to their chalky shells - Source : NASA's Earth Observatory (http:/earthobservatory.nasa.gov)
Average chlorophyll concentration in the surface ocean (from mi-September 1997 to August 2007) from the ocean color sensor SeaWiFS (NASA). Subtropical gyres, in the center of the oceanic basins, are characterized by very low concentrations of chlorophyll a (dark blue) - Source : NASA's Earth Observatory (http:/earthobservatory.nasa.gov)
Satellite observation (GEOS-12) of Hurricane Katrina in August 2005 in the Gulf of Mexico - Source : NASA-NOAA
The seasonal evolution of the chlorophyll a concentration as seen by a « water color » satellite (SeaWifs) in the Atlantic Ocean.
Rosette used to collect seawater samples during a scientific cruise in the South Pacific Ocean. During the austral summer, the amount of chlorophyll a is so low that the water becomes deep blue, almost purple. (Photo : Joséphine Ras)
